var JQueryUtilsDebug = false;


var JQueryUtils = function()
{
	return {
		visible : function(elem, isVis) 
		{
			if (elem)
			{
				elem.css({display:(isVis ? "block" : "none")});
			}
			else if (JQueryUtilsDebug)
			{
				alert('JQueryUtils.visible: Elem is null!');	
			}
		},
		
		check : function(elem, isChecked)
		{
			if (elem)
			{
				elem.attr("checked", (isChecked ? "checked" : ""));
			}
			else if (JQueryUtilsDebug)
			{
				alert('JQueryUtils.check: Elem is null!');	
			}
		},
		
		value : function(elem, val)
		{
			if (elem)
			{
				elem.val(val);
			}
			else if (JQueryUtilsDebug)
			{
				alert('JQueryUtils.value: Elem is null!');	
			}
		},
		
		onEvent : function(elem, evt, fn, data)
		{
			if (elem && evt)
			{
				elem.unbind().bind(evt, data, fn);
			} 
			else if (JQueryUtilsDebug)
			{
				alert('JQueryUtils.onEvent: Elem or event is null!');	
			}
		},
		
		unbindEvent : function(elem, evt)
		{
			if (elem && evt)
			{
				elem.unbind(evt);
			} 
			else if (JQueryUtilsDebug)
			{
				alert('JQueryUtils.unbindEvent: Elem or event is null!');	
			}
		},
		
		center : function(elem)
		{
			if (elem)
			{
				// work out x and y position of centre
				var xc = 0;
				var yc = 0;
				if ( window.innerHeight ) 
				{
					xc = Math.floor(window.innerWidth / 2);
					yc = Math.floor(window.innerHeight / 2);
				}
				else if ( document.documentElement.clientHeight )
				{
					xc = Math.floor(document.documentElement.clientWidth / 2);
					yc = Math.floor(document.documentElement.clientHeight / 2);
				}
				
				elem.css({
						position: "absolute",
						marginTop: 0,
						marginLeft: 0,
						left: xc - (elem.width() / 2), 
						top: yc - (elem.height() / 2)
					});
			}
		}
	};
}();